Casual Loop & Systems Diagrams - Problem Solving from MindTools. Understanding How Factors Affect One Another © iStockphoto/mevans System diagrams are powerful tools that help you to understand how complex systems work.

Systems analyzed may be anything from businesses, through biological population models, to the impact of social policy, etc. System diagrams are particularly helpful in showing you how a change in one factor may impact elsewhere. They are excellent tools for flushing out the long term impacts of a change. Drawing a system diagram is a good way of starting to build a computer model. How to Use the Tool Relationships Between Factors At the heart of the use of system diagrams is the idea of linking factors to show a relationship between them. For example a company may link the factors of product quality and customer satisfaction. The S shows that the factors move in the Same way – as quality improves, so will the happiness of customers. These relationships can also work the other way. Feedback Loops Balancing Loops Reinforcing Loops Gaps Delay. Www.optisim.org/QLENG/UserFiles/File/optisim.html. System Dynamics Methods: A Quick Introduction. This 125 page set of notes provides a quick introduction to system dynamics methods using business examples.

Vensim notation is used, and free versions of Vensim can be downloaded for instructional use from Ventana Systems, Inc. A quick reference and tutorial for Vensim can be downloaded from the ASU system dynamics resources page. This document is formatted for two-sided printing, and the blank pages at the end of some chapters are intentional so that new chapters will start on right-hand pages.

Effective January 12, 2013, this work is licensed under a Creative Commons Attribution-NonCommercial 3.0 Unported License. The document can be downloaded in either of two forms: Return to ASU system dynamics resources page. Archetypes - Interaction Structures of the Universe. Interaction Structures of the Universe This article is essentially a continuation of Systems Thinking: An Operational Perspective of the Universe in which the Reinforcing and Balancing structures were developed.

This article develops a set of frequently recurring structures resulting from various combinations of Reinforcing and Balancing structures. This article essentially represents an elaboration of the work of Senge (1990) and Pegasus Communications (1989-1996). Note that all the archetype examples that were previously wired into this article are now accessible via theWay which is considered to provide a more comprehensive treatment of the archetypes, as well as a few additional ones, and uses the "+" and "-" influence notation. Accidental Adversaries The Accidental Adversaries structure is a composed of three reinforcing loops and two balancing loops.

Balancing Loop (^) The Balancing Loop attempts to move some current state to a desired or reference state though some action. Isee systems - The World Leader in Systems Thinking Software. Www.simtegra.com - System dynamics modeling causal loop diagram software screenshots. Scenarios for Sustainability: Modeling Methods. This page contains a collection of modeling techniques on different subjects that are available online.

In addition to these sources, also see the Quantitative Modeling section on the “Scenario Toolkit” page on this site. Agent-Based Modeling The Agent-Based Modeling FAQ An On-Line Guide for Newcomers to Agent-Based Modeling in the Social Sciences Linear and Non-Linear Programming The Linear Programming FAQ The Nonlinear Programming FAQ Bayesian Belief Networks A tutorial on Probability Theory and Bayesian Belief Networks An Introduction to Bayesian Networks and their Contemporary Applications Systems Thinking and Causal Loop Diagrams System Dynamics Methods: A Quick Introduction, including instructions on causal loop diagrams Guidelines for Drawing Causal Loop Diagrams on The Systems Thinker site Catalogue of “archetypal” causal loop structures at the systems-thinking.org site Specific Models and Topics The GAMS Model Library at the site for the GAMS modeling system.